FIX: for degenerate tree with a single leave.

To render a tree with a single leave node,
the TriangleLookupTable range nneeds to be
modified.

Change-Id: If374953a8d658392cfd0f6bf5b5b620aa2dcea24
Another approach to fix this degenerate case

This commit resolves the error that were previously experiencing
when a tree was pruned down to a single leaf.  It does so without
changing the color lookup table for normal, collapsed leaves.  This
means that we do not have to update the baseline image to keep the
AutoCollapse test passing.

Change-Id: Idf4fc9e2f9ad2046f298623208769138c1bad841
fix Newick reader for named root vertex

Before this commit, the vtkNewickTreeReader would trash if you attempted
to load a file where the root vertex of the tree was named.

Change-Id: I1d1f282fc586a4a0b5569bb5d2e065dfe6a8aa7e
Merge topic 'TreeHeatmapItemFix' into master

156390e9 Another approach to fix this degenerate case
110169fd FIX: for degenerate tree with a single leave.
Merge topic 'newick_named_root' into master

a788e7ff fix Newick reader for named root vertex
Increment version to VTK 6.1.0

Change-Id: I754b471b2fe5b1fce74cf9d2848769583cfdd610